Display device and method of manufacturing the same

A display device comprising:

• an insulating substrate having a first surface;
• and
• a TFT element arranged on the first surface of the insulating substrate, wherein
• the TFT element includes a gate electrode, a gate insulating film, a semiconductor layer, and a source electrode and a drain electrode arranged in that order on the first surface of the insulating substrate,
• the semiconductor layer includes
• an active layer composed of polycrystalline semiconductor and
• a contact layer having a segment between the active layer and the source electrode and another segment between the active layer and the drain electrode,
• each contact layer segment is disposed on a side face of the active layer, and
• an insulating layer is disposed between the active layer and each of the source electrode and the drain electrode.

A method of manufacturing a display device, comprising the successive steps of:

• (a) forming a gate electrode on a first surface of an insulating substrate;
• (b) forming a gate insulating film over the gate electrode;
• (c) forming an active layer composed of polycrystalline semiconductor on the gate insulating film;
• (d) forming a semiconductor layer over the active layer, the kind and concentration of an impurity contained in the semiconductor layer being different from those in the active layer;
• (e) forming a conductive film on the semiconductor layer;
• (f) etching the conductive film to form a source electrode and a drain electrode;
• and
• (g) etching the semiconductor layer to form a contact layer segment disposed between the source electrode and the active layer and another contact layer segment disposed between the drain electrode and the active layer.